FIG. 1a illustrates a prior art protocol for opening a connection in the transmission control protocol/internet protocol (TCP/IP) network environment. The open connection protocol consists of a three way handshake. For the example illustrated in FIG. 1a, the open connection is between "node 1" and "node 2". In order to initiate the open connection, node 1 sends a segment having the SYN bits set in the code field. The node 2, in a second segment, sets both the SYN bit and ACK bits. This response by node 2 both acknowledges the first SYN segment as well as continues the handshake protocol with node 1. However, the second segment does not complete the protocol, but the second segment is a mere acknowledgment that is used to inform node 1, the initiator, that both sides agree that a connection has been established. In a third segment, the node 1 initiator sends an ACK segment back to node 2. After the connection has been established, data transfer may commence.
FIG. 1b illustrates the prior art protocol for closing a connection in accordance with the TCP/IP networking protocol. The closed connection protocol is a modified three-way handshake. For the example illustrated in FIG. 1b, node 1 initiates closing of the connection. The response from the node after receiving the initial FIN segment for the close connection of TCP/IP protocol is different from the open connection. As shown in FIG. 1b, instead of generating a second FIN segment immediately, node 2 sends an acknowledgment. In response to the initial FIN segment, the network interface informs an application of the request to close the connection. When the application instructs the network interface to close the connection, node 2 sends the second FIN segment, and node 1 replies in a third segment using the ACK segment.